A uniformly aligned multilayer of membranes containing peptides has one-dimensional structural order in which the bilayers are the unit cells and preserves the orientational order of peptides relative to the plane of membrane. Our goal is to develop methods to extract these structural information, and use such methods to study the structural bases of the voltage-gating mechanisms in model channels. In the past year, we have developed the method of oriented circular dichroism, by which we can indeed extract the orientational information of helical peptides in membrane. We have also found that our multilayer samples produce high resolution diffraction data, from which we can obtain the one- dimensional electron density profiles of peptides in bilayer membranes, in particular the position of heavy atomic ions. This report describes the application of these methods to study the voltage-gating mechanism of the alamethicin channel and the location of ion binding sites of the gramicidin channel. Keywords: Alamethicin; Melittin; Gramicidin; Oriented Circular Dichroism; X-ray Diffraction; Neutron Scattering; Perfectly Aligned Multilayers.
